I'm dying my hair pink. Help!?

Ok I am dying my whole hair pink. I have dyed my hair a lot of times, its been- Black, Platinum Blonde, Strawberry blonde, Ginger, Cherry Red, Brown and streaked/highlighted blonde. I am using Splat- fetish pink, hair color. And I have a box of Sammy Brand, Fat Foam Blonde hair dye. So do I dye my hair the blonde first then put the pink over it? How long am I supposed to wait between dying?? My hair is kinda thin but its getting healthier, Any tips or tricks I could use? [: thanks!